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Multiple choice physics effects of light scattering of light and its applications some natural phenomena of light natural phenomena explained by scattering

Tyndall effect is shown by:

  1. particles in colloidal solution.

  2. particles in a very fine suspension

  3. large particles like stones.

  4. both A and B
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The Tyndall Effect (Tyndall scattering), is light scattering by particles in a colloid or else particles in a very fine suspension. It is observed in aerosol, iris, milk, etc.

Multiple choice physics effects of light scattering of light and its applications some natural phenomena of light natural phenomena explained by scattering

Which of the following phenomenon is involved in Tyndall effect?

  1. Reflection of light.

  2. Refraction of light.

  3. Scattering of light.

  4. Magnification of light.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The Tyndall Effect (Tyndall scattering), is light scattering by particles in a colloid or else particles in a very fine suspension. The amount of scattering is inversely proportional to the fourth power of wavelength and hence the colour of the colloidal solution is the same as the least coloured wavelength.

Multiple choice physics effects of light scattering of light and its applications some natural phenomena of light natural phenomena explained by scattering

Which of the following quantities changes during the process of scattering?

  1. Speed.

  2. Wavelength.

  3. Direction of propagation.

  4. None of the above.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

After scattering, light is spread in all directions and hence the direction of propagation changes. Wavelength, speed and frequency of the light remains unchanged during the process. Also, the intensity of the light ray in a direction changes.

Multiple choice physics effects of light scattering of light and its applications some natural phenomena of light natural phenomena explained by scattering

Which of the following occurs in scattering?

  1. Light is reflected back in the original direction.

  2. Light is split into its spectrum.

  3. Photons in the light wave are absorbed by the particles.

  4. Absorption and re-emission of light energy by small particles.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Scattering is the process of absorption and then re-emission of light energy by particles smaller than the wavelength of the incident light ray. 

Multiple choice physics effects of light scattering of light and its applications some natural phenomena of light natural phenomena explained by scattering

After scattering, the light moves in:

  1. the same direction as the original light ray.

  2. opposite to the original direction of the light ray.

  3. all directions.

  4. the direction of the shortest path.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In scattering,  light wave is absorbed and re-emitted in all directions without a change in the wavelength of the light ray.

Multiple choice physics effects of light scattering of light and its applications some natural phenomena of light natural phenomena explained by scattering

Stars twinkle but planets do not twinkle because

  1. Stars emit their own light but planets receive light from the stars

  2. Stars do not from a part of solar system

  3. Stars from a point source of light while planets are considered as a collection of a large number of point sources of light

  4. During refraction of star light from the atmosphere, star light bends more towards the normal as compared to the planets
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Light of the star is bent  many times and in random directions  as light is bent when it hits a change in density. This random refraction results in the star winking out - twinkling. 

Planets are closer to Earth and so appear  as tiny disks in our sky.
The light from these little disks is also refracted by Earth’s atmosphere, as it travels toward our eyes. Due to the planets’ apparent closeness to Earth, the light coming from these celestial bodies does not bend much due to Earth’s atmosphere. Also being not a point source but appearing as disks, they comprise of several point sources- lights of which are coming at the same time. So a deviation in light path of one point source can cancel with deviations of other and would average out to give rise to a steady shine. Therefore, the light coming from our solar system’s planets does not appear to twinkle like stars.

Multiple choice physics effects of light scattering of light and its applications some natural phenomena of light natural phenomena explained by scattering

As the thickness of the atmosphere increases colour of scattered light is found in ________ order.

  1. Blue, violet, yellow, red

  2. Violet, blue, yellow, red

  3. Red, yellow, blue, violet

  4. Violet, blue, red, yellow
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The short-wavelength blue and violet are scattered by molecules in the air much more than other colors of the spectrum because of which blue and violet light reaches our eyes from all directions.

As thickness of atmosphere increase,  more molecules are available to scatter the violet and blue light away from our eyes. If the path is long enough, all of the blue and violet light scatters out of our line of sight.  and he other colors orange, red continue on their way to your eyes.
The sky often appears red because larger particles of dust, pollution, and water vapor in the atmosphere reflect and scatter more of the reds and yellows.
Option D 

Multiple choice physics effects of light scattering of light and its applications some natural phenomena of light natural phenomena explained by scattering

The clear sky appears blue because:

  1. blue light gets absorbed in the atmosphere.

  2. ultraviolet radiations are absorbed in the atmosphere.

  3. violet and blue lights get scattered more than lights of all other colours by the atmosphere.

  4. light of all other colours is scattered more than the violet and blue colour lights by the atmosphere.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The scattering of light depends on the size of the dust particles and the wavelength of the light. The amount of scattering is inversely proportional to the fourth power of wavelength.
Since, violet and blue lights get scattered more than lights of all other colours by the atmosphere the sky appears blue.

Multiple choice physics effects of light scattering of light and its applications some natural phenomena of light natural phenomena explained by scattering

What are the colours of the Sun observed most during sunrise/sunset and noon? 

  1. white and red

  2. reddish and orange

  3. yellow and reddish

  4. orange and blue
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

During sunrise and sunset the sun rays have to pass through a larger distance and also a greater thickness of air since it is low in the sky. At these positions, the sky looks orange-red colour because photons of red and orange light are least scattered through the atmosphere and are able to reach our eyes.